a. Field of the Invention
This invention relates to a system and method for ablation of cardiac tissue in a living being. In particular, the instant invention relates to a system and method for ablation of cardiac tissue via the esophagus using photodynamic therapy.
b. Background Art
It is well known to use ablation catheters to create tissue necrosis in cardiac tissue to correct conditions such as atrial arrhythmia (including, but not limited to, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter). Arrhythmia can create a variety of dangerous conditions including irregular heart rates, loss of synchronous atrioventricular contractions and stasis of blood flow which can lead to a variety of ailments and even death. It is believed that the primary cause of atrial arrhythmia is stray electrical signals within the left or right atrium of the heart. The ablation catheter imparts ablative energy (e.g., radio frequency energy) to the heart tissue to create a lesion in the heart tissue. This lesion disrupts undesirable electrical pathways and thereby limits or prevents stray electrical signals that lead to arrhythmias.
Ablation catheters are typically placed near the cardiac tissue to be treated in one of two ways. Access to endocardial tissue is obtained by inserting the catheter within a vessel located near the surface of a patient's body (e.g., in an artery or vein in the leg, neck, or arm) and maneuvering the catheter through the circulatory system to the internal heart chambers. Access to epicardial tissue may be obtained by making a subxiphoid incision in the patient's body. Although the use of ablation catheters in this manner has resulted in less invasive treatment of arrhythmias, it would be desirable to develop a system and method for treatment of cardiac tissue that is even less invasive than current methods.
The inventors herein have recognized a need for a system and method for ablation of cardiac tissue that will minimize and/or eliminate one or more of the above-identified deficiencies.